Legal ‘War’ Promised if Trump Tries to Clip California's Right to Set Air Standards

Any attempt to prevent California from setting its own clean air transportation standards would provoke "a war with many states lining up on California's side," Mary Nichols, chair of the California Air Resources Board, said.

"I can't say which court we would sue in or where" but CARB will aggressively oppose any attempts by the Trump administration to revoke the state's right to set clean air standards separate and stricter than the federal government's rules, Nichols said at a Bloomberg New Energy Finance conference in Palo Alto.

The Trump administration is considering giving automakers permission to backtrack on their commitments to achieve certain improvements in gasoline mileage and cuts in greenhouse gas emissions by 2025. Manufacturers now argue the requirements are too inflexible and technologically too hard to meet.